64-bit will only work if you have a 64-bit processor. I have XP-64bit on my computer and it has a lot of compatibility issues since you need the 64-bit version of the drivers for all of your hardware but since it is such an unpopular OS companies usually won't make the drivers. I am not sure if this is the same case as the 64-bit Vista OS but I would just stick with the 32-bit and I am sure that the processor that your laptop will have will be a 32-bit processor.